Since its launch on April 28 2003, iTunes has accrued a catalogue of more than 35 million songs and has around 435 million active account-holders across the world. On average, more than 15,000 songs are downloaded every minute and according to the technology website Pocket-lint, it would take more than 140,000 years to listen to every single music download available through the famous store.

Gennaro Castaldo, of HMV, said the music store - along with the iPod - had "undoubtedly" played a major part in changing the way consumers discover and listen to music. "Between them, they've helped to reshape the music landscape - in the process creating a commercially viable model for digital technology in much the same way the gramophone did for recordings some 100 years ago," he said.

"The challenge for Apple now is that digital consumers appear to be moving away from owned downloads to streaming, and there are now a growing number of competitors all looking to challenge their market dominance.

"Demand for physical product also remains surprisingly resilient and there's even been a mini-resurgence for formats like vinyl as some fans look for a more authentic music experience."

Cameron Farrelly, a music specialist at the advertising agency pd3, said: "Over the past 10 years iTunes has drastically changed the way we share, purchase and consume music. It has given us unrestricted and portable access to music's extensive back catalogue and taught the masses the art of a perfect playlist. iTunes have pioneered a listening revolution."

Eddy Cue, Apple's senior vice president of internet software and services, said the company took "great pride" in exposing music fans to new and emerging artists. He said: "When Apple introduced the iTunes Store on April 28, 2003, we thought if consumers had a great, legal way to download music they would embrace it - did they ever.

"Apple was floored, as were the labels, when customers bought over one million songs during the first week. And now, 10 years later, we continue to be amazed by how much customers love the iTunes Store with more than 25 billion songs sold."

The iTunes store is now available in 119 countries around the world. Besides its vast collection of music tracks, it holds more than 190,000 episodes of television programmes and more than 45,000 films.